I don't know a whole lot about 4 channel, but I use it 2-channel. Have it driving a couple of Duntech Lab loudspeakers from the same era in a 20 x22' hardwood floored room, creates a tight, thunderous subsonic base wave that is totally seperate from the rest of the mix. Mids and highs are very warm . I paid $100.00 for the speakers, (yea, Duntech--imagine that) that are beat, but looks are decieving. Puts any mid range system to shame and I think it rivals premium stuff (5k +) stuff that is out today. (of course, this is premium stuff here, vintage premium..)
The cold solderd board acts up from time to time, with a channel shutting down, bu it salways comes back for more.
I have used it outdoors at high current levels with the amps bridged for hours, and it could be heard clearly a quarter of a mile away. Zero discernable distortion.
That's my $130.00 system....viva vintage.

I don't know a whole lot about 4 channel, but I use it 2-channel. Have it driving a couple of Duntech Lab loudspeakers from the same era in a 20 x22' hardwood floored room, creates a tight, thunderous subsonic base wave that is totally seperate from the rest of the mix. Mids and highs are very warm . I paid $100.00 for the speakers, (yea, Duntech--imagine that) that are beat, but looks are decieving. Puts any mid range system to shame and I think it rivals premium stuff (5k +) stuff that is out today. (of course, this is premium stuff here, vintage premium..)
The cold solderd board acts up from time to time, with a channel shutting down, bu it salways comes back for more.
I have used it outdoors at high current levels with the amps bridged for hours, and it could be heard clearly a quarter of a mile away. Zero discernable distortion.
That's my $130.00 system....viva vintage.

due to age deterioration: sound not silky smooth compared to my cheapo Caiyin 256A class A 30WPC amps.

My friendly HiFi shop caught me driving by and told me that he had saved this one for me.
I bought it and never became sorry. I thought it was so good I loaned ti to my friend to have his opinion. He too thinks that this one is very good, and would have bought it if he were there!
OK here are my points of observation:
1. Quad decode is excellent. I play some of my non-quad and wued its vario-matrix to play the tracks. It was so good I thought that I had missed a good part of the quad era in history. Now this thing has put me in the search for the 70's quad things now that people have kept telling me I have gotten one of the best quad equipment pieces made druing the prime time of quads.
2. Tuner: very good. enough said.
3. Dolby circuit: the dolby tone level on the left channel is 1-2dB down. Oh yeah, it should be calibrated later. But I think its dolby circuit is good compared to my Nakamichi NR-200 dolby b/c codec. Too bad this part of the machine is no longer of any value to anyone today now that analogue tapes are almost obsolete.
4. Output: the 60W X 4, or 60W X 2 outputs are more than enough to me believe this thing should be rated aomewhere like 100 X 2 when operating in low power mode.
Its 120X2 high power mode is said to be troublesome as it cooks itself easily but I have tried using this mode for long time without problem. On my Allison AL-125, which is a medium efficiency (more like 86 dB@1W SPL as I feel), this mode is good to take the output to very loud levels without any slight hint of distortion or clipping. Still sounds open and uncompressed then.
5. Sound quality: I think I can’t too look in this department of the thing. After all, this might be a Class B design in amp stage (someone pls correct if I’m wrong), and was made that many years ago, something must have gone kabook. After all, I’m still impressed by its presentation of soundstage, being open, clean, accurate, but sometimes tube-like warm in highs and mids. I like its reproduction of human voices when fed my NAD Tuner 3225, which sound very comfortable to my ears. Not that there is any highs rolling off at audible frequencies, but the sound is just natural, warm, and non-distorted. The QRZ-9001’s FM tuner turns out equally hissless sound in stereo as well, but there is just this extra sense of natural touch to it with that set-up.
With my Philip DVP7205A and Allison AL-125 speakers, the sound from my QRX-9001 is again tube-like warm, non-distorted to my senses, open, natural, and above all, non-fatiguing for a number of type of music. This set-up is best when playing orchestral music, jazz, and female singing. Take any Lisa Ono, Jacintha, or a Four Seasons played by Felix Ayo and I Musici, or even a Tchaikovsky Symphony No. 4 of Bernard Haitink/Concertgebouw Orch. (Philips recording in the 70’s) , and you won’t be far from Hi-End results in terms of clarity with good warmth, open soundstage (given even high volumes). I just fear that the next level of HiFi performance might cost me hundredfold more.

due to age deterioration: sound not silky smooth compared to my cheapo Caiyin 256A class A 30WPC amps.

My friendly HiFi shop caught me driving by and told me that he had saved this one for me.
I bought it and never became sorry. I thought it was so good I loaned ti to my friend to have his opinion. He too thinks that this one is very good, and would have bought it if he were there!
OK here are my points of observation:
1. Quad decode is excellent. I play some of my non-quad and wued its vario-matrix to play the tracks. It was so good I thought that I had missed a good part of the quad era in history. Now this thing has put me in the search for the 70's quad things now that people have kept telling me I have gotten one of the best quad equipment pieces made druing the prime time of quads.
2. Tuner: very good. enough said.
3. Dolby circuit: the dolby tone level on the left channel is 1-2dB down. Oh yeah, it should be calibrated later. But I think its dolby circuit is good compared to my Nakamichi NR-200 dolby b/c codec. Too bad this part of the machine is no longer of any value to anyone today now that analogue tapes are almost obsolete.
4. Output: the 60W X 4, or 60W X 2 outputs are more than enough to me believe this thing should be rated aomewhere like 100 X 2 when operating in low power mode.
Its 120X2 high power mode is said to be troublesome as it cooks itself easily but I have tried using this mode for long time without problem. On my Allison AL-125, which is a medium efficiency (more like 86 dB@1W SPL as I feel), this mode is good to take the output to very loud levels without any slight hint of distortion or clipping. Still sounds open and uncompressed then.
5. Sound quality: I think I can’t too look in this department of the thing. After all, this might be a Class B design in amp stage (someone pls correct if I’m wrong), and was made that many years ago, something must have gone kabook. After all, I’m still impressed by its presentation of soundstage, being open, clean, accurate, but sometimes tube-like warm in highs and mids. I like its reproduction of human voices when fed my NAD Tuner 3225, which sound very comfortable to my ears. Not that there is any highs rolling off at audible frequencies, but the sound is just natural, warm, and non-distorted. The QRZ-9001’s FM tuner turns out equally hissless sound in stereo as well, but there is just this extra sense of natural touch to it with that set-up.
With my Philip DVP7205A and Allison AL-125 speakers, the sound from my QRX-9001 is again tube-like warm, non-distorted to my senses, open, natural, and above all, non-fatiguing for a number of type of music. This set-up is best when playing orchestral music, jazz, and female singing. Take any Lisa Ono, Jacintha, or a Four Seasons played by Felix Ayo and I Musici, or even a Tchaikovsky Symphony No. 4 of Bernard Haitink/Concertgebouw Orch. (Philips recording in the 70’s) , and you won’t be far from Hi-End results in terms of clarity with good warmth, open soundstage (given even high volumes). I just fear that the next level of HiFi performance might cost me hundredfold more.

Similar Products Used:

Pionss QR-8000A

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Dec 27, 2003]

Terry

Audio Enthusiast

Strength:

High power with excellent matrix decoding circuitry rivals any PRO LOGIC or Dolby DTS on the market today. Nice tuner display that moves in a lighted sign wave pattern when the knob is spun.
Push button matrix selection.

Weakness:

A totally manual system. Constantly having to get up and adjust for the sound I want. With the 5-way speakers I have it will hurt your ears before distorting. With the power up the higher frequencies must be suppressed or it is too clear. Takes up too mucj room for my small house. Have it boxed up until I move.

Bought in 1978 this receiver still kicks butt especially when matched with todays
surround systems. I use it with four Kenwood 888D speakers and a JVC S.E.A. equalizer amplifier.

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Dec 27, 2003]

Terry

Audio Enthusiast

Strength:

High power with excellent matrix decoding circuitry rivals any PRO LOGIC or Dolby DTS on the market today. Nice tuner display that moves in a lighted sign wave pattern when the knob is spun.
Push button matrix selection.

Weakness:

A totally manual system. Constantly having to get up and adjust for the sound I want. With the 5-way speakers I have it will hurt your ears before distorting. With the power up the higher frequencies must be suppressed or it is too clear. Takes up too mucj room for my small house. Have it boxed up until I move.

Bought in 1978 this receiver still kicks butt especially when matched with todays
surround systems. I use it with four Kenwood 888D speakers and a JVC S.E.A. equalizer amplifier.

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Oct 26, 2002]

qsd_dan

AudioPhile

Strength:

Fidelity, power, decoding, and, of course, looks. Upgradeable to support main amp and pre amp in and out jacks and operations. Good, strong FM tuner, which locks on hard to stations. Make plenty of room for this beast, it's a behemoth!!

Weakness:

All of these receivers suffer from cold solder joints on the Selector board which is an easy fix and well worth the effort (you'll notice it when channels start cutting in and out, or just plain cut out). Due to their age now, all of the capacitors need to be replaced to clearly hear it's full, unsurpassed potential (especially the power supply caps)

I originally purchased this receiver for their unequaled quadraphonic synth decoding. I ended up getting much more than I ever intended as these receivers have an unbelievable amount of power and superlative fidelity. They are the most conservativly underrated 60 watts per channel receiver I've EVER heard and put my 100 watt per channel Sony STR-DE985 receiver to serious shame!! The 9001 is most definatley a "high current" receiver and push all of my main speakers and subwoofers with immense ease emitting very deep, tight bass (has 8 speaker hook-up capacity). The type A, QS variomatrix decoding is STILL the king of decoders and embarrasses the Dolby Pro Logic II decoder from the Sony. Unbelievable fidelity, highs and mids are crystal clear and clean with the deepest, tightest, and punchiest bass one could ever want. These are some of the most beautiful receivers made with their analog tuner and power meters. Hands down a 5 star rating.

Similar Products Used:

Pioneer QX 949, Sansui QRX 7500 and several others.

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Oct 26, 2002]

qsd_dan

AudioPhile

Strength:

Fidelity, power, decoding, and, of course, looks. Upgradeable to support main amp and pre amp in and out jacks and operations. Good, strong FM tuner, which locks on hard to stations. Make plenty of room for this beast, it's a behemoth!!

Weakness:

All of these receivers suffer from cold solder joints on the Selector board which is an easy fix and well worth the effort (you'll notice it when channels start cutting in and out, or just plain cut out). Due to their age now, all of the capacitors need to be replaced to clearly hear it's full, unsurpassed potential (especially the power supply caps)

I originally purchased this receiver for their unequaled quadraphonic synth decoding. I ended up getting much more than I ever intended as these receivers have an unbelievable amount of power and superlative fidelity. They are the most conservativly underrated 60 watts per channel receiver I've EVER heard and put my 100 watt per channel Sony STR-DE985 receiver to serious shame!! The 9001 is most definatley a "high current" receiver and push all of my main speakers and subwoofers with immense ease emitting very deep, tight bass (has 8 speaker hook-up capacity). The type A, QS variomatrix decoding is STILL the king of decoders and embarrasses the Dolby Pro Logic II decoder from the Sony. Unbelievable fidelity, highs and mids are crystal clear and clean with the deepest, tightest, and punchiest bass one could ever want. These are some of the most beautiful receivers made with their analog tuner and power meters. Hands down a 5 star rating.

Similar Products Used:

Pioneer QX 949, Sansui QRX 7500 and several others.

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Mar 31, 2000]

obbop

Audio Enthusiast

Strength:

Power. Vario-Matrix circuitry synthesizes stereo into quad in a most groovy manner. Lots of hook-ups for all the goodies you wanna' plug in. Excellent Sansui craftsmanship

Weakness:

None, so far.

Whoooooo Baby!!!! If yah' wanna' get a retro thrill with quadraphonic sound... this is the receiver to get.Some prefer the Marantz 4400, but, in my never humble opinion, the Sansui QRX-9001 is the best due to the Vario-Matrix circuitry.

Power galore and extremely low THD. I haven't heard ANY of the modern surround sound stuff perform as well when doing audio only.

These units are getting a premium price. Nice units on the eBay auction site have been going for $700 to $900 American. Wow!!!! That should give yah' an idea of the value placed on these units by quaddies.

For info about quad, check out this site

:http://homestead.deja.com/user.obbop/Index.html

The product year choices are limited. My unit is a 1976 model bought on Okinawa by an Air Force pilot that brought it back to the states. I got it ridiculously cheap in 1995. Keep yer' eyes open.... if yah' gets a chance... grab one and dig the retro quad sound!!!

Similar Products Used:

QRX-7500

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Mar 31, 2000]

obbop

Audio Enthusiast

Strength:

Power. Vario-Matrix circuitry synthesizes stereo into quad in a most groovy manner. Lots of hook-ups for all the goodies you wanna' plug in. Excellent Sansui craftsmanship

Weakness:

None, so far.

Whoooooo Baby!!!! If yah' wanna' get a retro thrill with quadraphonic sound... this is the receiver to get.Some prefer the Marantz 4400, but, in my never humble opinion, the Sansui QRX-9001 is the best due to the Vario-Matrix circuitry.

Power galore and extremely low THD. I haven't heard ANY of the modern surround sound stuff perform as well when doing audio only.

These units are getting a premium price. Nice units on the eBay auction site have been going for $700 to $900 American. Wow!!!! That should give yah' an idea of the value placed on these units by quaddies.

For info about quad, check out this site

:http://homestead.deja.com/user.obbop/Index.html

The product year choices are limited. My unit is a 1976 model bought on Okinawa by an Air Force pilot that brought it back to the states. I got it ridiculously cheap in 1995. Keep yer' eyes open.... if yah' gets a chance... grab one and dig the retro quad sound!!!

Similar Products Used:

QRX-7500

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Jun 17, 1999]

Dan Stoll

an Audio Enthusiast

Purchased this unit two months ago, it is like having a 4 channle 9090db, all the same features just two more channles.Don't have specs or manuals. If someone knows for sure could you e-mail me. Great Unit !

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

★★★★★

★★★★★

[Jun 17, 1999]

Dan Stoll

an Audio Enthusiast

Purchased this unit two months ago, it is like having a 4 channle 9090db, all the same features just two more channles.Don't have specs or manuals. If someone knows for sure could you e-mail me. Great Unit !

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

★★★★★

★★★★★

[Feb 11, 2000]

KC Dierkes

Audio Enthusiast

Strength:

Best quad synth section ever, built to survive atomic blasts at ground zero

Weakness:

One circuit board has failure-prone design

I own two of these, and simply have to say they are unparralled in the short history of quad receivers. The QRX-9001 has the hands down best quad synthesizer circuit of all time, and the decoder is excellent as well. Only the TATE II can exceed the decoder quality, based at least on gear that I personally have listened to.

These have a power supply with juice to spare (no clipping here guys) and a surprisingly good tuner for a receiver. One of the more unique dial glass/front panel designs I've seen in several years on collecting vintage equipment.

Physically it is a beast, weiging a good 60 pounds, and being larger than any other receiver Sansui ever made with the exception of the G-22000 and G-33000 "docking" receivers. Get a reinforced entertainment center if you buy one of these beauties, it'll splinter garbage pressboard furniture.

If you see one of these, snatch it before someone else does. Do be forewarned though, these can be the Jaguar of hi-fi. Nice to drive on the weekend, but spend the rest of the time in the shop due to cold solder joints on one of the circuit boards in the control section. Once those are fixed, you would be hard pressed to find a more reliable unit.

I've owned mine since 1995/96, but they were made between '73 and '78. I just can't praise the design and quality of the QRX-9001 enough, and fully expect to be buried with mine.

Similar Products Used:

Sansui QRX-3000, Sansui QRX-7001

OVERALLRATING

5

★★★★★

★★★★★

VALUERATING

5

★★★★★

★★★★★

[Feb 11, 2000]

KC Dierkes

Audio Enthusiast

Strength:

Best quad synth section ever, built to survive atomic blasts at ground zero

Weakness:

One circuit board has failure-prone design

I own two of these, and simply have to say they are unparralled in the short history of quad receivers. The QRX-9001 has the hands down best quad synthesizer circuit of all time, and the decoder is excellent as well. Only the TATE II can exceed the decoder quality, based at least on gear that I personally have listened to.

These have a power supply with juice to spare (no clipping here guys) and a surprisingly good tuner for a receiver. One of the more unique dial glass/front panel designs I've seen in several years on collecting vintage equipment.

Physically it is a beast, weiging a good 60 pounds, and being larger than any other receiver Sansui ever made with the exception of the G-22000 and G-33000 "docking" receivers. Get a reinforced entertainment center if you buy one of these beauties, it'll splinter garbage pressboard furniture.

If you see one of these, snatch it before someone else does. Do be forewarned though, these can be the Jaguar of hi-fi. Nice to drive on the weekend, but spend the rest of the time in the shop due to cold solder joints on one of the circuit boards in the control section. Once those are fixed, you would be hard pressed to find a more reliable unit.

I've owned mine since 1995/96, but they were made between '73 and '78. I just can't praise the design and quality of the QRX-9001 enough, and fully expect to be buried with mine.